Evidence suggests that if current dietary guidelines for Americans were enriched for edible plants and fiber and had a reduced fat content then adopting such a diet might lead to a 30-50% decline in recurrence of localized breast cancer after the disease has been diagnosed and treated by conventional means. Although epidemiological studies have collinearity problems in trying to sort out a single nutrient as the effective anticarcinogen, the available data from both epidemiological and laboratory studies suggest that any anticarcinogenic effect of diet probably will not be explained by the ingestion of a single macronutrient (e.g., fat). We are performing a multi-center randomized trial comparing the American Cancer Society/National Cancer Institute dietary guidelines to a diet that is very high in fruits and vegetables, high in micro nutrients, and very low in fat. A pilot study at the University of California, San Diego, proved the feasibility of the experimental diet with a doubling of intake of vegetables, increase in dietary fiber by 50%, and a reduction in calories from fat by 30%. Targeted intake was maintained by 80% for at least 12 months. Our goal is the accrual of 3,000 breast cancer survivors who are within four years of their diagnosis of stage I (>1 cm), stage II or stage III disease, and who have completed conventional therapy. To date, we have demonstrated we can enroll subjects at the rate required for a four-year intake period. As of February 1, 1999, a total of 1,773 subjects had been randomized to the study by seven participating institutions, with 221 subjects enrolled by the Northern California Cancer Center at Stanford Unversity site.